Here is an excerpt of an article by Sarah Birch where she analyzes the value of the IPCC report:

“To those, however, who make it their business to be informed consumers of the science and policy surrounding the climate change issue, there are a number of criticisms of the IPCC that must be considered. First, it has been said that the IPCC is a highly selective body, choosing for participation only those scientists who fall in line with the overarching message, which is pre-determined. While this is partially true (it is common for authors who have participated in past reports to be invited to participate in future reports, thereby ensuring a certain consistency of message), it must be remembered that the output of the IPCC is widely circulated to critics and supporters alike during four excruciatingly drawn-out rounds of review. This includes hundreds of experts in the fields of atmospheric physics, ecology, hazards management, epidemiology, economics, political science and engineering (to name but a few), as well as members of think-tanks, governments, lobby organizations, activist groups, and Non-Governmental Organizations. No other scientific publication can claim to encircle such a broad range of perspectives. While clearly the opinions of these various parties cannot be accepted en masse, each and every comment is considered in detail by the author teams. Each suggested publication is reviewed, each new idea debated, and each fact checked. I’m exhausted just thinking about the amount of effort.

Despite this excessively thorough procedure, the lovingly and painstakingly prepared documents remain the whipping-boy of a host of scientific critics. Of course I wouldn’t dare imply that some of these critics are simply petulant children who haven’t been asked to play, or that, in claiming that the participating scientists are only trying to secure funds for their personal research agendas, some critics are clawing for the same goody-basket of funding dollars themselves. Indeed, it is carefully considered and analytical criticism that forms the foundation and rigour of science itself, so these vocal opponents must not be silenced. We must be vigilant, however, for in the broader (often rather fatigued) public consciousness, even a whisper of impropriety surrounding a document or organization that calls for uncomfortable levels of change on the part of governments, industry, and individuals is enough to cause us to change the channel and forget the message.

So, despite the output of the IPCC being a highly politicized and (fairly or unfairly) controversial beast, we must use the Fourth Assessment Report as a tool with which we can capture the current climate fanaticism. This unprecedented level of public awareness may be exactly what is needed to pass laws and formulate policies that are more forward-thinking than ever before in the short history of industrial capitalist economies. We have the opportunity to prove to our descendents that we are neither apathetic nor lacking in empathy and foresight, and that our vast stores of ingenuity can be used to solve the problems that our ingenuity created in the first place. Carbon neutrality, after all, is not a pipe dream but a concrete reality that can be achieved using tools and technologies already in circulation. Furthermore, the seeds of dissatisfaction with an existence based solely on consumption have long since been sowed, and climate change may provide an unparalleled opportunity to fundamentally restructure the stories that we tell about our culture. In the absence of alternatives to scientific collaboratives on the scale of the IPCC, we must use what tools we have to alter the story of the 20th and 21st centuries from one of degradation, consumption, poverty, waste and violence to one of innovation, foresight, equity, and peace.”